Depressed senior

The course that depression takes may change one’s vulnerability to dementia, and depression treatment may play a large role in that risk, a new study finds.

The researchers, from institutions in China and the United Kingdom, sought to uncover associations between depression outcomes, treatment and the risk of new dementia diagnoses. To do so, they followed health outcomes in more than 350,000 patients from the U.K. biobank between the ages of 50 and 70 for up to 14 years. 

Participants with depression had a 51% elevated risk for dementia when compared to non-depressed participants — a not-unexpected finding in light of numerous prior studies linking the two conditions. But the study also found that participants with high- or low-level chronic depression, or increasing depression, had greater odds of developing dementia when compared to their peers with a decreasing course of depression. The latter participants faced no greater risk for dementia than their peers without depression, reported Wei Cheng, PhD, of Fudan University, in China, and colleagues.

Treatment and risk

The investigators also looked at the effect of depression treatment on risk. They found that overall, patients treated for depression had a 30% lower odds of developing dementia when compared to their peers with untreated depression. 

When data on the course of depression was analyzed, participants with increasing and chronically low courses of depression who got treatment for depression were less likely to subsequently have a dementia diagnosis. In contrast, treatment did not appear to affect dementia risk for participants with chronically high courses of depression. 

“This indicates that timely treatment of depression is needed among those with late-life depression,” Cheng said in a statement. “Providing depression treatment for those with late-life depression might not only remit affective symptoms but also postpone the onset of dementia.”

Full findings were published in the journal Biological Psychiatry.

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